This invention relates generally to means for slowing the rate of liquid run-off from developed residential or commercial real estate tracts so that the rate of run-off from a developed tract does not exceed the natural rate of run-off from the same tract prior to its development. More specifically, this invention relates to a system which employs conventional rock particle filled, wire boxes, known as gabion boxes, which are conventionally used to stabilize a vertical earth cut or earth wall and a porous fabric or perforated sheet attached to and covering one or more of the vertical sides of the boxes such that liquid run-off can flow from a developed real estate tract into the gabion boxes and, thereafter, be discharged at a preselected rate to a stream, storm sewer, storm drain or the like.
In many governmental jurisdictions in this country it is required by law or ordinance that the rate of storm water run-off from a proposed residential or commercial development to be built on a tract of land must not exceed the natural rate of storm water run-off from the tract which existed prior to the proposed development. In some cases, a xe2x80x9cvariancexe2x80x9d can be obtained from the appropriate governmental agency to permit the rate of storm water run-off from the proposed real estate development to be some preselected percentage greater than the natural storm water run-off rate of the undeveloped tract of land on which the development is to be built. In other special cases, a more stringent requirement may be required wherein the storm water run-off rate of the proposed development will be less than the natural run-off rate of the undeveloped tract by some fractional amount or percentage.
To this end, it has been the practice in the prior art to form ponding areas, install underground pipes or build underground vaults on the tract to be developed to temporarily accumulate and store storm water flowing therein from above and from other sections of the property to slow the rate of storm water run-off from the property as a whole. Ponding areas are usually resorted to where there exists an undeveloped low area of the tract, which will not contain buildings, roadways, parking areas or other improvements, to which storm water can drain from other areas of the tract, both developed and undeveloped. Underground pipes having both means for draining surface run-off into them and for discharging the run-off at a preset rate to streams or storm sewers are resorted to where the surface area above the pipes is developed into paved parking areas, side walks, roadways and the like. The drain rate from such ponding areas, underground pipes and vaults to streams, storm sewers and the like for conveyance off of the tract can, of course, be closely controlled by well known means such as, for example, by using weirs, orifices or valves on outlet ports of the pipes. But the use of ponding areas, for example, for the temporary storage of run-off can, in many instances, unduly limit the amount of development permissible on a given tract of land. In some cases, the only area of a tract suitable for containing a ponding area may also be the most desirable area for development, thus limiting proposed development to less suitable areas of the tract.
By means of my invention, these and other difficulties encountered using conventional storm water run-off control facilities is substantially reduced, if not altogether eliminated.
It is an object of my invention to provide a novel storm water detention filter system for limiting the rate of storm water runoff from a developed tract of land to an amount no greater than that naturally occurring on the tract prior to development.
It is a further object of my invention to provide an elongated storm water detention filter that eliminates the need for dedicating a broad surface area of a tract as a storm water pond or impoundment basin which, as a consequence, can not be developed.
Briefly, in accordance with my invention there is provided a storm water detention filter system which includes at least one gabion box filled with rock particles for receiving storm water runoff from a tract of land therein. The filter system also includes at least one sheet of porous, liquid permeable material attached to and covering at least one vertical surface of the gabion box for reducing the flow rate of storm water passing through the box and sheet from the tract to a storm drain.
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and attached drawings upon which, by way of example, only a preferred embodiment and certain other important embodiments of my invention are described and illustrated.